JEE MAIN - Mathematics (2009 - No. 20)
Let A and B denote the statements
A: $$\cos \alpha + \cos \beta + \cos \gamma = 0$$
B: $$\sin \alpha + \sin \beta + \sin \gamma = 0$$
If $$\cos \left( {\beta - \gamma } \right) + \cos \left( {\gamma - \alpha } \right) + \cos \left( {\alpha - \beta } \right) = - {3 \over 2},$$ then:
A is false and B is true
both A and B are true
both A and B are false
A is true and B is false
ব্যাখ্যা
